Verbenone

How do I use Verbenone for tree protection?

Synergy Semiochemicals has been providing high quality Verbenone to our customers for over 10 years as part of an integrated pest management plan for land owners, foresters, researchers and government agencies throughout Canada and the United States.

Verbenone is not a conventional pesticide and is not toxic to animals or the environment. It is a registered product with EPA in the USA. Currently we can only supply Verbenone to USA customers.

Verbenone is an antiaggregation pheromone for Mountain pine beetle (Dendroctonus ponderosae), Southern pine beetle (Dendroctonus frontalis), Western pine beetle (Dendroctonus brevicomis) and other bark beetles. Verbenone, as a stand alone product, is normally only deployed to deter mass attack of Mountain Pine Beetle in tree stands. It has not been proven as a single pheromone deterrent for tree protection from Southern Pine Beetle, Western Pine Beetle, or Ips species.

Mountain Pine Beetle (MPB), Dendroctonus ponderosae Hopkins, is a bark beetle that infects Western pine, Jack Pine, Lodgepole and Ponderosa Pine in Canada and the USA.
MPB normally have a one-year life cycle but in colder climates and also higher elevations they have the potential to overwinter and adapt to a two or three year life cycle. If they have a life cycle greater than one year they will still only have one clutch of eggs. This indicates that the beetles can adapt to climate changes in order to survive.

Generally, in late summer, adult females emerge when ambient air temperature exceeds approximately 16ºC or 61ºF. The adults are about 5 mm (1/4”) long when they bore through the bark and fly away from the infected pine trees. The female beetle then releases an aggregation pheromone to initiate mass attack of living trees and to attract males. The female beetles tunnel into pine trees and lay eggs in vertical galleries under the bark. In the galleries, females mate with males in mid-summer and lay eggs individually along the sides of the gallery. Female MPBs will lay approximately 60 eggs. After mating, the beetles produce anti-aggregation pheromones including Verbenone. The Verbenone is synthesized by intestinal and gallery-inhabiting microbes within the MPB. A high concentration of Verbenone lets flying beetles know the tree is already full to capacity and acts like a ‘no vacancy’ sign. This natural mechanism is used by MPB to avoid overcrowding under the bark and usually stops the mass attack on the pine trees.

After about two weeks, the eggs hatch; the grub-like larvae make horizontal galleries and overwinter under the protective bark. The larvae resume feeding in spring and grow up to 7 mm in length. They can resist -35° temperatures for several days. Larvae pupate in the spring and emerge as adults from July to September.

Part of the destructiveness of Mountain pine beetles is the transmission of blue-stain fungi from the beetle to the tree. The spores of these fungi are brought into the tree by adult beetles during colonization. Fungi grow within the tree while the beetle larvae feed, which weakens and eventually kills the tree. This mutual network of beetle galleries and blue stain fungi disrupts the movement of food and water between the roots and needles and rapidly kills the tree. The fungi give a blue-grey appearance to the sapwood.

Where to use Verbenone

Verbenone can be used to help prevent attack of Mountain pine beetle – Dendroctonus ponderosae. It has not been proven as a single pheromone deterrent for tree protection from Southern Pine beetle – Dendroctonus frontalis, Western Pine beetle – Dendroctonus brevicomis, Red Turpentine beetle – Dendroctonus valens, or Ips species.

Verbenone pouches or bubbles can be deployed on stands containing pine trees of any species, including limber, loblolly, lodge pole, pinyon, shortleaf, Virginia, western white, and whitebark.

Verbenone is not toxic and can be used on trees in forests; municipal and shade tree areas; recreational areas such as campgrounds, riparian areas, golf courses, parks and parkways; ornamental and shade tree plantings; suburban areas; and rights of way and other easements. Verbenone should not be applied directly to streams, lakes, ponds or any body of water.

When and how to apply Verbenone?

Synergy Shield Verbenone Pouches and Bubbles (USA only)

Verbenone products have been commercially produced for over 10 years. Traditionally, Verbenone is loaded into small credit-card sized plastic pouches that act as slow-release devices once deployed on a tree. Verbenone diffuses through the plastic membrane and is released into the surrounding area much the same way as if they were released naturally by Mountain Pine Beetle. The scent or “plume” of Verbenone signals to arriving beetles to move on to find another location.

The Verbenone pouches have been sold by other manufacturers with a load of about 6.75 – 7 grams each. Synergy Shield Verbenone pouches (USA only) contain 7.85 gm, the highest dosage currently available in a pouch. The higher dose gives extra protection in areas of heavy beetle infestation without having to apply an additional mid-season refresher pouch.

We recognized that in areas of mild to moderate Mountain Pine Beetle infestations where pine trees are sparse and grid placement becomes costly, a lower dosage of Verbenone is desirable. We have created a Synergy Shield Verbenone bubble (USA only) containing 0.98gms each. The bubble cap is a made of a plastic membrane that also acts as a slow-release device once deployed on a tree. Synergy Shield bubbles can be used on perimeters of infestation areas for a first line of defense, interspersed in densely populated stands to help blanket a larger area with the Verbenone plume or directly on valuable trees to boost the protective dose.

The Verbenone plume from a pouch or a bubble has about a 12 foot (4-5 meter) radius. Beyond this distance, trees will be more susceptible to attack. When planning your repellent strategy, you should deploy pouches and/or bubbles at a dose of 150 gm Verbenone/acre to ensure protection.

If you are a USA customer and not sure whether to use a Synergy Shield 7.85 gm pouch, the 0.98gm bubble or a combination of both, please call us. We would be happy to assist with an individualized protection strategy to maximize the effectiveness of Verbenone.

Both Synergy Shield Verbenone products are manufactured with state of the art manufacturing equipment in our Canadian warehouse. By manufacturing and selling direct to you, without an intermediary, we can offer these high quality products with exceptional prices.

Deployment of Verbenone

For best results, remove all beetle-infested trees on the property before application. Trees should be removed or debarked before the expected beetle flight in the spring. Once 40% of the trees in the area are infested, the product efficacy may be reduced.

Verbenone may be used with pheromone baited traps to help reduce population pressure. For more information, see our push-pull strategy.

The Verbenone pheromone diffuses through the rectangular plastic membrane and is released into the surrounding area. The pheromone plume radius is a maximum of 12 ft (4-5 meters). Beyond this distance, trees will be more susceptible to attack. When planning your repellent strategy, you should deploy pouches and/or bubbles at a dose of 150 gm Verbenone/acre to ensure protection. The release rate is also affected by wind speed and direction.

Place Synergy Shield Verbenone on trees at least 2 weeks prior to expected flight of the pest. Under normal weather conditions Synergy Shield Verbenone is effective for 70-100 days, spanning an entire season. Use a second treatment as needed if conditions are extreme.

Our new Verbenone bubble (USA only) contains 0.98g of Verbenone and gives you more options to protect your trees.

Choose Synergy Shield Verbenone bubbles in areas of mild to moderate infestations where pine trees are sparse and grid placement becomes costly. You can also add Verbenone bubbles in densely populated stands or at perimeters for additional protection.

Choose Verbenone pouches in areas of higher infestations or for larger areas where grid placement is more efficacious.

With two Verbenone products to choose from, you can save money and/or maximize the effectiveness of Verbenone.

Useful Tips

Verbenone is sold in multiples of 10 and is priced for volume discounts. We encourage you to place a bulk order to maximize your savings.

Rule of thumb: Place Verbenone pouches or bubbles no more than 12 feet apart for maximum dosage.

If you plan on using Verbenone from one year to the next in the same location, clip a corner so you can tell which ones are from last year.

Keep unused Verbenone in an airtight container (glass canning jars or a metal paint can with tight lid are perfect), in a cold shed, garage or freezer until ready to use. Keep in the freezer for use next year.

For best results it is critical to remove infested trees off site well before beetle-flight.

If possible keep your trees well watered.

DO NOT PUNCTURE RESERVOIR!! Doing so will release the Verbenone immediately. The plastic membrane is a special plastic that allows the Verbenone to release into the area slowly.

Application rates for Verbenone Pouches (USA only)

Individual trees and area 1 acre or less:

Place 1 or 2 Verbenone pouch on each tree depending on risk of attack and size of tree.

For large trees over 24 inches diameter, add 1 more Verbenone pouch for each additional 12 inches in diameter, 3 feet above the previous Verbenone.

Perimeter Protection:

On contour of perimeter, place 1 Verbenone pouch every 15 feet along length of perimeter. Move in 30 feet and repeat with a second line.

At high beetle pressure place 1-2 Verbenone pouch /tree in a grid pattern.

Application rates for Synergy Shield Verbenone bubbles (USA Only)

Placement on trees: Place Synergy Shield Verbenone bubbles on north face of susceptible trees by stapling individual bubbles at 6 to 12 feet high. Attach to tree using flashing on device being careful not to puncture the reservoir.

Individual trees and area 1 acre or less:

Place 2-6 Synergy Shield Verbenone bubbles on each tree depending on risk of attack and size of tree.

On contour of perimeter, place 1 to 4 Synergy Shield Verbenone bubbles on each susceptible tree, depending on size. Continue placing Synergy Shield Verbenone bubbles on susceptible trees to a depth of 45 – 120 feet from the perimeter.